Nowadays, very small devices are produced by micro machine technology and widely used in various technical fields. Examples of such devices include micro mirror devices, angular velocity sensors and acceleration sensors, all of which are provided with a tiny movable member. Among these, micro mirror devices are used for light reflection, in the field of e.g. optical disks or optical communication. Angular velocity sensors and acceleration sensors are utilized for providing e.g. a camera shake compensation system of video cameras or camera-equipped mobile phones, a car navigation system, an airbag release timing system, and an attitude control system of automobiles or robots. Typically, a micro movable device includes a stationary portion, a movable member, a connecting portion to connect the movable member to the stationary portion, and a driving mechanism for generating a driving force to move the movable member. The driving force may be adjustable so as to control the displacement of the movable member in operation. Conventional micro movable device are described, for example, in International Publication Pamphlet No. WO 2004/034124, Japanese Laid-open Patent Publication No. 2006-162663, and US Patent Application Publication No. 2004/0119376.